1. Field of the Invention
The present invention relates to a device for absorbing harness slack to prevent slack in wire harness associated with opening or closing of a door for the purpose of continuously supplying such as a sliding door of vehicles with electricity.
2. Description of the Related Art
In vehicles such as minivans or wagons, it is necessary to supply a sliding door with electricity continuously regardless of whether said sliding door is open or closed so as to employ such as electrical components or accessories therein, or an automatic open/close actuator for said sliding door in a vehicle body.
For this purpose, a wire harness made of plurality of electric wires is arranged from a vehicle body into a sliding door, supplying with electricity or distributing electric signals. It is necessary that the wire harness inside the sliding door should be expanded or contracted according to open/close condition of the sliding door and absorb the wire harness slack so as not to being caught in a gap between the sliding door and the vehicle body by the slack when closing the sliding door.
For this purpose, a device for absorbing harness slack is proposed as shown in FIG. 13. In this device for absorbing harness slack 80, substantially a semi-circular shaped protector 81 made of synthetic resin accommodates a wire harness 82 in a curved shape and a metal leaf spring 84 urges a curved portion 83 of the wire harness 82 in a direction of upholding the wire harness 82. A cap (guiding member) 85 made of synthetic resin is fixed on an end part of the metal leaf spring 84, supporting the wire harness 82 without any damage.
The wire harness 82 is expanded when the sliding door is closed, while the wire harness 82 is contracted to be curved in a small radius inside the semi-circular shaped protector 81 when the sliding door is open. The metal leaf spring 84 prevents the wire harness 82 from dropping down especially at the time of opening the sliding door by means of upholding the wire harness 82 without any slack. The cap 85 is formed thicker than the metal leaf spring 84, so that the cap 85 resolves confliction between the wire harness 82 and the end part of the metal leaf spring 84, preventing the wire harness 82 from being damaged.
However, in the conventional device for absorbing harness slack 80 as above described, since the end part of the cap 85 abuts against the wire harness 82, the curved portion 83 of the wire harness 82 tends to be supported at one point. In this case, as shown in FIG. 14, there is a worry that the wire harness 82 may be folded (86) to make it difficult for the wire harness 82 to shift slidably on the cap 85. In the event of the wire harness 82 being folded, an angle of the curve cannot be guaranteed, and the expansion or contraction of the wire harness 82 and the slack absorbing of the wire harness 82 will not take places smoothly at opening or closing the door and so forth. Further, some folding remains in the wire harness 82, generating a trouble that electric wires composing the wire harness 82 tend to be broken due to repetition of curving the electric wires.
The present invention has been accomplished to solve the above-described problems and an object of the present invention is to provide a device for absorbing harness slack which is able to prevent the wire harness from folding due to the cap (guiding member) abutting against the wire harness, so that the expansion or contraction of the wire harness and the slack absorbing of the wire harness take places smoothly and surely at opening or closing the door and so forth.
In order to attain the above described object, there is provided, according to a first aspect of the present invention, a device for absorbing harness slack comprising a resilient member and a harness-guide member mounted on the resilient member, the harness-guide member supporting a curved portion of a wire harness slidably, wherein the harness-guide member comprises a harness-support surface curved throughout its length in a direction of the curved portion.
With this configuration, for example, when a diameter of the curved portion of the wire harness is expanded or contracted by the expansion or contraction of the wire harness according to opening or closing the door, the harness-support surface of the harness-guide member continuously ensures the degree of curving of the wire harness, allowing the curved portion to shift smoothly and slidably without any folding.
Therefore, this configuration prevents any curl from remaining in the wire harness, allowing the wire harness to being expanded or contracted smoothly and surely, and preventing electric wires composing the wire harness from being broken or suffered with age.
There is provided, according to a second aspect of the present invention, a device for absorbing harness slack comprising a resilient member and a curved harness-guide member mounted rotatably on the resilient member, the harness-guide member supporting a curved portion of a wire harness slidably, whereby the harness-guide member is allowed to rotate in a curving direction of the wire harness.
With this configuration, the curved harness-guide member ensures a degree of curving of the wire harness, preventing the wire harness from folding when expanding or contracting. Moreover, the harness-guide member rotates according to the expansion or contraction of the diameter of the curved wire harness portion, keeping the degree of curving of the wire harness more surely.
Therefore this configuration allows the wire harness to being expanded or contracted smoothly and surely, preventing electric wires composing the wire harness from being broken or suffered with age.
There is provided, according to a third aspect of the present invention, the device for absorbing harness slack described above as the second aspect of the present invention, wherein a coupling member intervenes between the resilient member and the harness-guide member, and the harness-guide member is coupled rotatably with the coupling member.
With this configuration, the harness-guide member is fastened to the resilient member using the coupling member easily and surely. Moreover, the coupling member improves the rotatability of the harness-guide member.
According to the third aspect of the present invention, since the harness-guide member is fastened to the resilient member using the coupling member easily and surely, an assembling workability is improved. Moreover, the coupling member improves the rotatability of the harness-guide member to further promote an effect of the second aspect of the present invention.
There is provided, according to a fourth aspect of the present invention, a device for absorbing harness slack comprising a protector accommodating a wire harness in a curved shape, and a resilient member urging to absorb the harness slack, wherein a curved harness-guide member supporting the wire harness is mounted on the protector rotatably, and the resilient member urges the harness-guide member in a direction of absorbing harness slack.
With this configuration, while the curved harness-guide member ensures the degree of curving of the wire harness, the resilient member urges the harness-guide member in a direction of absorbing the slack according to the expansion or contraction of the diameter of the curved wire harness portion, and the harness-guide member rotates to absorb the wire harness slack corresponding surely to diameter fluctuation of the curved wire harness portion. Moreover, the harness-guide member mounted on the protector blocks excessive diameter contraction of the wire harness, preventing excessive bending of the resilient member.
According to the fourth aspect of the present invention, therefore, this configuration allows not only to prevent the wire harness from folding when expanding or contracting, but also to expand and contract the wire harness smoothly and surely, preventing electric wires composing the wire harness from being broken or suffered with age. Moreover, since providing the resilient member and the harness-guide member separately eliminates a need of assembling with each other, an assembling workability is improved. Furthermore, since the harness-guide member mounted on the protector blocks the excessive diameter contraction of the wire harness and prevents excessive bending of the resilient member, this configuration prevents such as the wire harness from damaging when opening or closing a sliding door roughly and so forth, and eliminates a need of providing a harness bending regulator. Thus, a structure of the protector is simplified.
There is provided, according to a fifth aspect of the present invention, the device for absorbing harness slack described above as the fourth aspect of the present invention, wherein either an end part of the resilient member or a cap at the end part of the resilient member supports slidably the harness-guide member.
With this configuration, when expanding or contracting the diameter of the curved wire harness portion, the resilient member shifts slidably and smoothly along a bottom surface of the harness-guide member, so that expanding or contracting a diameter of the wire harness, namely, expanding or contracting of the wire harness takes place smoothly and surely.
According to the fifth aspect of the present invention, therefore, a slack absorbability of the harness is improved, while abrasion and abnormal noise between the resilient member and the guiding member are prevented.
There is provided, according to a sixth aspect of the present invention, the device for absorbing harness slack described above as any of the second to fifth aspects of the present invention, wherein the harness-guide member has a harness-support surface being curved in the direction of the curved portion throughout its length.
With this configuration, the curved harness-support surface is stuck to the curved wire harness portion, keeping the degree of curving of the wire harness surely, and preventing the curved wire harness portion from folding.
According to the sixth aspect of the present invention, therefore, both a slack absorbability and an expanding or contracting ability of the harness are improved.
There is provided, according to a seventh aspect of the present invention, the device for absorbing harness slack described above as the first or sixth aspect of the present invention, wherein the harness-support surface composes a groove curved in a circumferential direction of the wire harness.
With this configuration, the wire harness is engaged with the groove, being supported stably without any displacement radially.
According to the seventh aspect of the present invention, therefore, the expansion or contraction of the diameter of the curved wire harness portion takes place more smoothly and surly, while such as friction between the wire harness and an interior of the protector is prevented so that both abrasion and abnormal noise of the wire harness are prevented.